The present invention relates to a throttle valve driving mechanism comprising an oscillating slide block mechanism disposed between a throttle valve and an actuator thereof, said driving mechanism maintaining desired air flow characteristics by increasing the resolution of air flow control in a range of small opening angles of the valve and by increasing the speed of the valve action in a range of large opening angles of the valve.
When a throttle valve for an internal combustion engine is actuated by means of an actuator, the valve is required to control air flow precisely with a high resolution in a range of small opening angles thereof and also to move between a fully closed position and a fully opened position as quickly as possible. The actuator of the valve is desired to have a small power, small size and light weight. If only the resolution of air flow control is taken into account, the speed of the valve action is decreased. On the other hand, if only the speed of the valve action is taken into account, the resolution of air flow control is decreased.